It's a matter of treaty law. States punched out a treaty on drugs and then promised each other to stick to it, pressuring other states to buy in.
Leaving a treaty means you change your relation to the other signatories and possibly a regulatory body that took part in developing the treaty. Sometimes it's cheap, sometimes it's been a justification for horrible atrocities over decades and decades.
In this case the latter is true. Ditching the UN convention is almost like saying you owe a lot of people restitution for the nasty things you did.
Which is why the UN needs to take the blame for the convention on drugs to go away, the signatories most likely won't.
Leaving a treaty means you change your relation to the other signatories and possibly a regulatory body that took part in developing the treaty. Sometimes it's cheap, sometimes it's been a justification for horrible atrocities over decades and decades.
In this case the latter is true. Ditching the UN convention is almost like saying you owe a lot of people restitution for the nasty things you did.
Which is why the UN needs to take the blame for the convention on drugs to go away, the signatories most likely won't.